One of my specialties as a Witch is crystal work. Crystals can work in conjunction with herbalism, and identification of elements related to crystals is important. One good book is Cunningham's Encyclopedia of Crystal, Gem and Metal Magic by Scott Cunningham. Crystal Medicine by Marguerite Elsbeth. All the books by Katrina Raphaell. It took a while to understand the significance of rainbows in crystals. I had crystals that had no rainbows at all. As I worked with many I noticed more rainbows appearing so I selected some which had no rainbows at all. One specific crystal was very stubborn but after a year I noticed a rainbow peeking out of it. So more smuding, more working, until more rainbows started to appear. I had doused that crystal before and after with a 15 inch string with an 8 mm bone bead and the energy from the crystal was noted to increase significatly from before I started when it had no rainbows. One thing with crystals is you have to be patient. All the crystals I have with rainbows have a significant more powerful charge. The stubborn quartz crystal is now beginning to blossom as it is devlopping more rainbows. Crystals with rainbows are activated. Messages from other Witches I know have exprienced the same thing. One sent me a picture of her massive crystals bathing in a natural spring loaded with rainbows. So if you have a crystal with no rainbows don't give up. Work with it. As you work with it it will channel.
Expanding on my "stubborn crystal" above. It is a polished obelisk point 6 inches long 1.5 inches diameter. I was at a mineral gem show and was ready to leave so I took a shortcut through a vendor I knew from experience. He was a vendor of Brazilian crystal, bulk, and tons of it. His motivation was more of qualtity and profits and I always avoided his area when I went to this particular show. Yet I looked as I walked through and then I saw this crystal to which I was pulled to. I picked it up and I suddenly felt a feeling of saddness, loss. I am psychic. I used to be a Tarot reader at psychic show events before Covid. Now I do long distance reading, select one on one and I teach a class on Tarot. I also can feel emotion, get messages as I touch something or someone. Does not happen all the time but when the energy is strong I will feel it. I immediately bought it and was part of my buying package. There are many what I call inner veils one finds in a crystal and I checked it out under sunlight, electric light, candle light, light from different times of the day and it was always the same-white veils throughout not one rainbow. On and off I worked with it until I got serious and had it with me at shows, just about everywhere. Then one day a rainbow peeked out and I got more determined with smudging, working the crystal. That was a year later, and then all these rainbows started to appear, its energy increased as I noticed though dousing it. Personally, what I get is that this crystal was plucked from its home and "processed" for profit. It shut down. it took care and respect to re-activate it. We have to be sensitive to crystals if we decide to have them. They are teachers. Give them the respect they deserve.